New file and open options grayed out

I cannot create a new file or open any file, actually nearly everything in my File drop down is grayed out. It was working fine less than an hour ago, restarted due to other problems no PS related. And now this! Key shortcuts don't work nor does dropping an image on to PS.I just opened from CC app, it finally allowed me to drag an image to PS to open it, closed it to retry it, then the cursor changed when dragging the same image on to PS - the red circle cancel icon! Why is it so bipolar!